The present invention relates to a threaded connecting assembly, more particularly to a threaded connecting assembly for forming a fluid connection between two fluid conduits in a manner providing high pressure durability, wear resistance, and rapid sealing therebetween.
Compressed fluids including gas, liquid and combinations thereof, are widely used throughout the food industry. Carbon dioxide gas and inert gases such as argon, helium, and nitrogen are extensively utilized for carbonation and food preservation, for example. Such food processing operations typically employ a fluid dispensing apparatus, a fluid source for supplying pressurized fluid, and a means for fluidly connecting the fluid source to the fluid dispensing apparatus. The fluid source is usually in the form of a compressed gas-containing cylinder which can store pressurized gas at pressures ranging from about 35 to 2,700 pounds per square inch (p.s.i.).
Such gas-containing cylinders typically include a fluid-tight vessel body with a cavity therein. The vessel body has a tapered neck with an outlet located at one end thereof. The cylinder is composed of a metal material for durability and strength. The compressed gas-containing cylinder may be sealed with a plate crimped at an outlet end for providing safe storage and transport. In order to dispense the compressed gas in a controlled manner, a fluid dispensing apparatus is ordinarily employed. The neck of the cylinder is mated with the gas port of the apparatus where a connecting pin is adapted to pierce through the cylinder plate for releasing the gas contents therethrough.
Generally, there are two types of cylinders used in the industry: those having threads and those that are unthreaded. Unthreaded cylinders are the most common and economical. However, fluid dispensing apparatuses which utilize such unthreaded cylinders usually require an assembly for positioning the cylinder to provide a secure fluid connection. The assembly holds the cylinder neck in position against the port, and applies a sufficient force to the cylinder to drive the neck end into the connecting pin for puncturing the plate and forming a fluid connection therebetween. Fluid connections of this type are disadvantageous because the cylinder neck is simply press fitted into position against the port which can result in leaking of the fluid at the junction of the cylinder neck and port.
Threaded cylinders typically include narrow, tapered threads extending along the surface of the cylinder neck. The threads substantially improve the quality of the fluid seal in the connection and provide a fluid connection which is more resistant to shock and vibration as compared to unthreaded fluid connections. However, the narrow, tapered threads cost substantially more to fabricate, have relatively low wear resistance and thread strength, and require many screw-turns for adequate seating within the port. These and other limitations associated with such threaded cylinders have restricted their use.
It would be a significant advance in the art of threaded connectors to provide a threaded connecting assembly for use especially with a compressed fluid which overcomes many of the limitations associated with prior art threaded connectors. The threaded connecting assembly of the present invention is constructed in a cost efficient and effective manner having minimal parts while providing the benefits of high thread strength, high pressure durability, ease of use, high wear resistance, and rapid-sealing.
The present invention is generally directed to a threaded connecting assembly comprising:
a first threaded connecting member having a body portion, an end portion, a bore extending axially from the end portion enabling the passage of a fluid through the body portion, and a plurality of spaced apart three sided threads defining grooves therebetween projecting along an exterior surface of the body portion at the end portion; and
a cap member having a plurality of complementary three sided threads adapted to mate with the plurality of the three sided threads of the first threaded connecting member by seating in the grooves, and an opening configured for engagement with the bore of the first threaded connecting member to provide a passageway for the flow of the fluid therebetween.